HPLC Determination of ZnPT in Marine Paint

A method of HPLC for the determination of ZnPT in marine paint was proposed. The sample (0.020 0 g) was extracted for 10 min ultrasonically with ethyl acetate (10 mL). An aliquot of 5 mL of the supernatant was derivatized with 5 mL of 0.5 mol·L-1 Cu(NO3)2 solution. Agilent ZORBAX Eclipse XDB-C18 chromatographic column with mixtures of acetonitile and water with different mixing ratios as mobile phase in the gradient elution. UV-detection with DAD at 242 nm was adopted in the determination. Linear relationship between values of peak area and mass concentration of ZnPT was kept in the range of 0.25-200 mg·L-1 with detection limit (3S/N) of 14 mg·kg-1. Tests for recovery were made by standard addition method at 3 concentration levels, giving values of recovery in the range of 89.3%-92.9% with RSD′s (n=6) less than 3.0%.